In semiconductor technology, the wafers, each having multiple dies, are produced by a plurality of processes and stages in a wafer fabrication facility (FAB). Each process or stage may introduce one or more defects into the semiconductor wafer, which leads to quality and reliability issues, failures, and yield losses. To improve manufacturing technology and enhance wafer quality, reliability, and yield, the semiconductor wafers are measured, tested, monitored, and diagnosed at each process and at each stage.